Text messaging, or Short Message Service (SMS), is a service that allows short (e.g., 140 bytes or 160 characters) messages to be sent from and received by mobile devices, such as cell phones, smart phones, wireless personal digital assistants (PDAs), etc. The service facilitates transmission and reception of messages over control channels associated with wireless communication links, rather than over typical voice or data channels associated with the communication link. Multiple messages may be chained together to create messages that exceed 140 bytes in length. Such multiple messages may be used to transmit and receive long text messages, or non-text content, such as, for example, mobile ring tones for a mobile device or graphics for display as background images in a mobile device (e.g., wallpaper).
SMS messages may also be used to obtain information services. For example, an SMS information or search system (“SMS information system”) may enable a user to send a query as an SMS message from a mobile device. In response, the SMS information system may provide one or more text messages that respond to the user's query. As a more particular example, a user may send a text message to an SMS information system that requests weather information for a particular city; in response, the SMS information system may provide one or more text messages that include weather information for the corresponding location, such as, for example, a current weather description, including temperature, humidity, and wind speed, and a forecast for the next day or two. As another example, a user may send a text message to the SMS information system, where the message requests phone number and address information corresponding to a person in a particular city; in response, the SMS information system may provide one or more text messages that include a phone number and address for the corresponding person.
Messages used to obtain information may require a special format, based on a particular information service requested. For example, the format of an SMS message requesting weather information may be different than the format of an SMS message requesting phone number or address information of a person. More particularly, a user may be required to include certain keywords in a text message requesting an information service in order to identify the desired service, or the user may be required to average query terms (e.g., a name of the city for which weather is requested, or a name of a person and a city) in a particular order, and the user may further be required to use particular punctuation.
The SMS information system may only process SMS information requests that are formatted as the SMS information system expects. In some cases, a mobile device user may be charged for each SMS message that he or she sends or receives, regardless of whether the message yields the intended result (e.g., provides desired information).